At least 300 people were killed and thousands injured in a strong earthquake that struck the Iraq-Iran border on Sunday night.
The 7.3 magnitude quake hit 30 kilometers (19 miles) southwest of Halabja in Iraqi Kurdistan at around 9.20 pm (1820 GMT) on Sunday, when many people would have been at home, the US Geological Survey said.
Iran's state-run news agency put the country's death toll in the quake at 341 people killed. IRNA's report on Monday afternoon also raised the number of injured, to 5,953.
Local officials told state TV that the death toll would rise as search and rescue teams reached remote areas of Iran. Only seven were reported killed on the Iraq side of the border, said the country’s Interior Ministry. Some 307 people were wounded.
The mountainous nature of Iran-Iraq border triggered landslides that hindered rescue efforts, officials said Monday.
The earthquake was felt in several western provinces of Iran but the hardest hit province was Kermanshah, which announced three days of mourning. More than 142 of the victims were in Sarpol-e Zahab county in Kermanshah province, about 15 km (10 miles) from the Iraq border.
State television said the quake had caused heavy damages in some villages where houses were made of earthen bricks. Rescuers were laboring to find survivors trapped under collapsed buildings.
Iran's emergency services chief Pir Hossein Koolivand said it was "difficult to send rescue teams to the villages because the roads have been cut off... there have been landslides".
IRNA said 30 Red Cross teams had been sent to the quake zone, parts of which had experienced power cuts.
President Hassan Rouhani is due to visit the areas damaged by the earthquake on Tuesday.
In Iraq, footage posted on Twitter showed panicked people fleeing a building in Sulaimaniyah, as windows shattered at the moment the quake struck, while images from the nearby town of Darbandikhan showed major walls and concrete structures had collapsed.
In Sulaimaniyah, residents ran out onto the streets and some damage to property was reported, an AFP reporter there said.
"Four people were killed by the earthquake" in Darbandikhan, the town's mayor Nasseh Moulla Hassan told AFP.
A child and an elderly person were killed in Kalar, according to the director of the hospital in the town about 70 kilometers (40 miles) south of Darbandikhan, and 105 people injured.
The quake, which struck at a relatively shallow depth of 25 kilometers, was felt for about 20 seconds in Baghdad, and for longer in other provinces of Iraq, AFP journalists said.
"I was sitting with my kids having dinner and suddenly the building was just dancing in the air," said Majida Ameer, who ran out of her building in the capital's Salihiya district with her three children. "I thought at first that it was a huge bomb.
Similar scenes unfolded in Irbil, the capital of the Kurdistan Region, and across other cities in northern Iraq, close to the quake's epicenter.
In Halabja, local officials said a 12-year-old boy died of an electric shock from a falling electric cable.
Iraq's meteorology center advised people to stay away from buildings and not to use elevators, in case of aftershocks.
Electricity was cut off in several Iranian and Iraqi cities, and fears of aftershocks sent thousands of people in both countries out onto the streets and parks in cold weather.
The Iranian seismological center registered around 118 aftershocks and said more were expected. The head of Iranian Red Crescent said more than 70,000 people were in need of emergency shelter.
On the Iranian side of the border, the tremor shook several cities in the west of the country including Tabriz.
Iran's police, the elite Revolutionary Guards and its affiliated Basij militia forces were dispatched to the quake-hit areas overnight, state TV reported.
Iranian Interior Minister Abdolreza Rahmani Fazli said some roads were blocked and authorities were worried about casualties in remote villages. An Iranian oil official said pipelines and refineries in the area remained intact.
The quake was also felt in southeastern Turkey, "from Malatya to Van", an AFP correspondent said. In the town of Diyarbakir, residents were reported to have fled their homes.
Turkish Red Crescent Chairman Kerem Kinik told broadcaster NTV that Red Crescent teams in Irbil were preparing to go to the site of the earthquake and that Turkey’s national disaster management agency, AFAD, and National Medical Rescue Teams (UMKE) were also preparing to head into Iraq. AFAD’s chairman said the organization was waiting for a reply to its offer for help.
Sunday’s quake struck along a 1,500 kilometer fault line between the Arabian and Eurasian tectonic plates, a belt extending through western Iran and into northeastern Iraq.
The area sees frequent seismic activity.
In 1990, a 7.4-magnitude quake near the Caspian sea in northern Iran killed 40,000 people and left 300,000 more injured and half a million homeless. Within seconds the quake reduced dozens of towns and nearly 2,000 villages to rubble.
Thirteen years later, a catastrophic quake struck the ancient southeast Iranian city of Bam, famed for its mud brick buildings, killing at least 31,000 people and flattening swathes of the city.
Since then, Iran has experienced at least two major quake disasters, one in 2005 that killed more than 600 and another in 2012 that left some 300 dead.
More recently, a 5.7-magnitude earthquake near Iran's border with Turkmenistan in May killed two people, injured hundreds and caused widespread damage.